In pipes and ducts subject to temperature extremes, radial and longitudinal expansion thereof may render support design critical. The support structure, which must provide adequate securement for the pipe or duct, will often act in opposition to expansion and contraction forces thereby inducing significant stresses in the pipe or duct member. The result can be premature and costly failure.
To date, there have been various suggestions proposed as solutions for this problem. For example, supports have been proposed wherein the pipe or duct is welded to rocker-support rings. Although the pipe or duct is free to expand and contract longitudinally, high local stresses are imposed on the pipe or duct wall. Other suggestions include rigidly attaching the pipe or duct to support rings or straps which are suspended by spring-biased hangers. These supports permit longitudinal expansion and provide vertical and lateral support. However, the support rings or straps tend to restrict radial expansion. Moreover, because the spring biased support pivots, longitudinal expansion and contraction tend to result in elevational changes in the pipe or duct, which is particularly undesirable when connecting to sensitive machinery.
Accordingly, it is desirable to have an apparatus to support a pipe and duct that provides adequate lateral and vertical support, but does not resist radial and longitudinal expansion, and maintains centerline elevation throughout operational temperature changes.